Five years after burying his father, Samuel W. Moore could no longer find the grave.

That was 1976, and Mount Auburn Cemetery, one of the oldest African-American burial grounds in the country, was overcome with stickerbushes, weeds and garbage — a fate unbecoming the scores of people buried there who were pioneers of Baltimore's black community.

After decades of neglect, interrupted occasionally by well-meaning but ultimately fruitless cleanup efforts, the cemetery in South Baltimore was officially rededicated Monday, due in large part to the labors of an unlikely group: state prison inmates.

As part of a program to put those serving time to work on meaningful projects, more than 40 prisoners have worked on the four-year effort to transform the cemetery's 34 acres.

"There's 55,000 graves here," said Gary Maynard, the secretary for the state's Department of Public Safety and Correctional Services, looking out over Mount Auburn's bright green fields. "That's 55,000 families. There are a lot of people connected to this cemetery, and now they're out here looking for graves of family they couldn't find in the past."

Since Maynard took over the department in 2007, inmates have planted 50 million oysters in the Chesapeake Bay, built a retaining wall along the C&O Canal, and restored the woods north and west of the Antietam Battlefield, among other projects.

It's a far cry from picking up trash on the side of the road. Maynard calls the efforts "restorative justice." He has sought to double the number of inmates working on such projects.

Founded in 1872, when blacks could not be interred next to whites, Mount Auburn was known as "The City of the Dead for Colored People." The cemetery, which overlooks the Middle Branch of the Patapsco River, became the final resting place for many pioneers of Baltimore's black community.

They include Lillie May Carroll Jackson, who led the Baltimore chapter of the NAACP for 35 years; Carl J. Murphy, a leading voice of the civil rights movement, and his father, John Henry Murphy, the founder of the Afro-American newspaper; and Joseph Gans, the first lightweight boxing champion.

"Successive generations of colored people around the Baltimore area have been buried at this site," said the Rev. Douglas B. Sands Sr., an area pastor who was been involved with efforts to restore the cemetery.

But over the years, Sharp Street Memorial United Methodist Church, which owns the cemetery, found it could not maintain the grounds, which cost an estimated $25,000 per year.

Over the years, caskets and human remains have emerged periodically from the earth. Members of the nearby Mt. Winans community said the cemetery's sagging fences, overgrown weeds and tilted headstones were an eyesore.

Dorothy Johnson, 70, has relatives buried at Mount Auburn.

"They didn't foresee that they need to do perpetual care, and to have the money to constantly come in there," she said. "It takes money; everything takes money."

Church members and local students would take part in cleanups, filling dozens of trash bags, only for the same problems to resurface.

Gov. Martin O'Malley recalled riding through the area before Election Day in 1999. "What is all that over there?" he asked state Sen. Joan Carter Conway. The cemetery was indiscernible.

"Mount Auburn Cemetery is the resting place of generations of Baltimore's African-American history, but until now many of those stories hae been covered and hidden by debris, by sticker bushes, by weeds and by blowing trash," O'Malley said at Monday's re-dedication ceremony. "Surely, a people united by our belief in the dignity of every human being can do better than what we had been able to do here, and now we have."

On a given day, there are more than 110 inmate crews performing labor outside the walls of a prison, according to John Rowley, who coordinates the state prison system's Public Safety Works program. Last year, they contributed more than 700,000 hours of work.

Future projects are expected to include the demolition of the old Maryland House of Corrections, which Maynard said will be the largest such project by inmates in the country, and will give inmates skills in asbestos and lead paint abatement.

Corrections officials hope such skills and the experience working on a team will help inmates prepare for a return to society. Those who have participated in such projects have a reduced rate of recidivism.

Not just any inmate can participate in the program, Maynard said. To be eligible, prisoners must have committed less-serious crimes, be nearing release, and earn their way into the program. They earn "a dollar or two" a day for their labor, officials said.

Learning about the historical significance of the sites is built into much of the work.

Maynard said the inmates who worked around Antietam "probably didn't know the history of the Civil War."

"They didn't know what sacrifice was made, for both sides, for saving the Union and state's rights," he said. "So all of a sudden, they're a part of history. That's going to help them change their mentality and what they're worth as a person."

Maynard credited outgoing Baltimore Police Commissioner Frederick H. Bealefeld III for suggesting Mount Auburn as a potential project. Bealefeld watched Monday's event with his staff, under some trees far from the assembled press and public officials. He declined to comment, saying he wanted attention to focus on the corrections department and the inmates.

The inmates who worked most recently on Mount Auburn cemetery were allowed to attend Monday's event, and shook hands with O'Malley.

During their time on the project, prisoners attended services at Sharp Street, and church members brought them food during their shifts.

Inmates said they found the response from the community fulfilling.

"What are you getting out of sitting in a prison cell?" asked Michael Toder, a 35-year-old from Charles County who is nearing release for a sentence for arson, according to court records. "Something like this gives you an opportunity to give back, to pay your debt back."

Johnson, a member of the Mount Auburn Cemetery board of directors who performs research to help people locate graves of their loved ones, said the inmate labor was "a blessing" for everyone involved.

Supporters of the project say their work is not done: Grave markers need to be straightened out, and some graves remain unidentified. The grass will continue to grow; the weeds will come back.

The Abell Foundation kicked in $90,000 for the project. Jeanne Hitchcock, the chair of the Mount Auburn Cemetery board of directors, said the church is focused on creating an endowment.

"One of the impediments [to creating an endowment] has been that people didn't see any progress," Hitchcock said. "Now that we've taken that giant step of clearing it up and getting partners involved, we can talk about sustainability. What we cannot do at this point is lose ground."

When Sherman Harris first saw the church grounds in 1988, he cried.

The 77-year-old Potomac man, a volunteer with the United Methodist Church, helped on various efforts over the years to clean up the grounds.

"I'm a person of faith," Harris said. "But I didn't think I'd see it in this present state."